Differential Effects of Proinflammatory Cytokines on TGF-β1-Mediated Biomechanical and Biochemical Properties of 3D Human Fibroblast TissuesdissertationsSt. Angelo, KaterinacreatorMorgan, JeffreyAdvisorHorrigan, DianaReaderY. Schell,, JacquelynReaderBrown University. Biology and Medicine: Biotechnologysponsor202610, 47 p.born digitalThesis (Sc. M.)--Brown University, 2026thesesFibrosis is driven by excessive extracellular matrix (ECM) deposition and is a hallmark of chronic diseases including pulmonary fibrosis, liver cirrhosis, and cardiac fibrosis. TGF-β1 is the primary driver of fibroblast activation, promoting myofibroblast differentiation, collagen synthesis, and increased tissue stiffness. However, the fibrotic environment contains a diverse array of proinflammatory cytokines that may modulate TGF-β1’s effects on fibroblasts. To investigate this, we used a scaffold-free 3D in vitro ring tissue model in which human fibroblasts self-assemble into a collagen-rich connective tissue over 14 days. Ring tissues were treated with TNF-α, IL-18, IL-1β, IFN-γ, or IL-1α, alone and in combination with TGF-β1. Tissue size, total DNA, total collagen, biomechanical properties (ultimate tensile strength and maximum tangent modulus), and histology were assessed at days 7 and 14. TGF-β1 increased collagen accumulation and the strength and stiffness of ring tissues. TNF-α, IL-1β, and IL-1α each reduced tissue size, total collagen, and the tensile strength and stiffness of both control and TGF-β1-stimulated tissues, effectively counteracting TGF-β1-mediated collagen accumulation. Histological analysis revealed that TNF-α and IL-1β disrupted collagen fiber architecture and increased nuclear pyknosis, effects that were most pronounced in TGF-β1-stimulated tissues. In contrast, IL-18 and IFN-γ had little to no effect on collagen accumulation or tissue mechanics in either control or TGF-β1-stimulated tissues. These findings demonstrate that proinflammatory cytokines have divergent effects on fibroblast-mediated collagen deposition: TNF-α, IL-1β, and IL-1α act as counter regulators of TGF-β1-driven fibrosis, while IL-18 and IFN-γ are largely neutral in this context. This work highlights the complexity of cytokine crosstalk in fibrosis and demonstrates the utility of 3D in vitro tissue models for dissecting cytokine-specific contributions to collagen accumulation and tissue biomechanics.microtissueFibrosis3D Cell Culture3D cel ring modelEnglishRPB20260427